Module: Adapter::Nokogiri

Defined in:
lib/premailer/adapter/nokogiri.rb

Instance Method Summary collapse

Instance Method Details

#load_html(input) ⇒ Object

Returns an Nokogiri document.



166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
 
# File 'lib/premailer/adapter/nokogiri.rb', line 166

def load_html(input) # :nodoc:
	thing = nil
	
	# TODO: duplicate options
	if @options[:with_html_string] or @options[:inline] or input.respond_to?(:read)
		thing = input
		elsif @is_local_file
		@base_dir = File.dirname(input)
		thing = File.open(input, 'r')
		else
		thing = open(input)
	end

  if thing.respond_to?(:read)
    thing = thing.read
  end
	
	return nil unless thing
	
	doc = nil

    # Default encoding is ASCII-8BIT (binary) per http://groups.google.com/group/nokogiri-talk/msg/0b81ef0dc180dc74
    if thing.is_a?(String) and RUBY_VERSION =~ /1.9/ 
     thing = thing.force_encoding('ASCII-8BIT').encode!
    doc = ::Nokogiri::HTML(thing) {|c| c.noent.recover }	    
  else
    doc = ::Nokogiri::HTML(thing, nil, 'ASCII-8BIT') {|c| c.noent.recover }
   end
	
	return doc
end

#to_inline_css ⇒ Object

Returns a string.



7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
 
# File 'lib/premailer/adapter/nokogiri.rb', line 7

def to_inline_css
  doc = @processed_doc
  @unmergable_rules = CssParser::Parser.new

  # Give all styles already in style attributes a specificity of 1000 
  # per http://www.w3.org/TR/CSS21/cascade.html#specificity
  doc.search("*[@style]").each do |el| 
    el['style'] = '[SPEC=1000[' + el.attributes['style'] + ']]'
  end

  # Iterate through the rules and merge them into the HTML
  @css_parser.each_selector(:all) do |selector, declaration, specificity|
    # Save un-mergable rules separately
    selector.gsub!(/:link([\s]*)+/i) {|m| $1 }

    # Convert element names to lower case
    selector.gsub!(/([\s]|^)([\w]+)/) {|m| $1.to_s + $2.to_s.downcase }
  
    if selector =~ Premailer::RE_UNMERGABLE_SELECTORS
      @unmergable_rules.add_rule_set!(CssParser::RuleSet.new(selector, declaration)) unless @options[:preserve_styles]
    else
      begin
        # Change single ID CSS selectors into xpath so that we can match more 
        # than one element.  Added to work around dodgy generated code.
        selector.gsub!(/\A\#([\w_\-]+)\Z/, '*[@id=\1]')

        doc.search(selector).each do |el|
          if el.elem? and (el.name != 'head' and el.parent.name != 'head')
            # Add a style attribute or append to the existing one  
            block = "[SPEC=#{specificity}[#{declaration}]]"
            el['style'] = (el.attributes['style'].to_s ||= '') + ' ' + block
          end
        end
      rescue  ::Nokogiri::SyntaxError, RuntimeError, ArgumentError
        $stderr.puts "CSS syntax error with selector: #{selector}" if @options[:verbose]
        next
      end
    end
  end

  # Read STYLE attributes and perform folding
  doc.search("*[@style]").each do |el|
    style = el.attributes['style'].to_s
  
    declarations = []

    style.scan(/\[SPEC\=([\d]+)\[(.[^\]\]]*)\]\]/).each do |declaration|
      rs = CssParser::RuleSet.new(nil, declaration[1].to_s, declaration[0].to_i)
      declarations << rs
    end

    # Perform style folding
    merged = CssParser.merge(declarations)
    merged.expand_shorthand!
      
    # Duplicate CSS attributes as HTML attributes
    if Premailer::RELATED_ATTRIBUTES.has_key?(el.name)       
      Premailer::RELATED_ATTRIBUTES[el.name].each do |css_att, html_att|
        el[html_att] = merged[css_att].gsub(/;$/, '').strip if el[html_att].nil? and not merged[css_att].empty?
      end
    end
  
    merged.create_dimensions_shorthand!

    # write the inline STYLE attribute
    el['style'] = Premailer.escape_string(merged.declarations_to_s)
  end

  doc = write_unmergable_css_rules(doc, @unmergable_rules)

  if @options[:remove_classes] or @options[:remove_comments]
    doc.traverse do |el|
      if el.comment? and @options[:remove_comments]
        el.remove
      elsif el.element?
        el.remove_attribute('class') if @options[:remove_classes]
      end
    end  
  end

  if @options[:remove_ids]
    # find all anchor's targets and hash them
    targets = []
    doc.search("a[@href^='#']").each do |el|
      target = el.get_attribute('href')[1..-1]
      targets << target
      el.set_attribute('href', "#" + Digest::MD5.hexdigest(target))
    end
    # hash ids that are links target, delete others
    doc.search("*[@id]").each do |el|
      id = el.get_attribute('id')
      if targets.include?(id)
        el.set_attribute('id', Digest::MD5.hexdigest(id))
      else
        el.remove_attribute('id')
      end
    end
  end

  @processed_doc = doc
if is_xhtml?
	@processed_doc.to_xhtml
else
  	@processed_doc.to_html
	end
end

#to_plain_text ⇒ Object

Converts the HTML document to a format suitable for plain-text e-mail.

If present, uses the <body> element as its base; otherwise uses the whole document.

Returns a string.



144
145
146
147
148
149
150
151
152
 
# File 'lib/premailer/adapter/nokogiri.rb', line 144

def to_plain_text
  html_src = ''
  begin
    html_src = @doc.at("body").inner_html
  rescue; end

  html_src = @doc.to_html unless html_src and not html_src.empty?
  convert_to_text(html_src, @options[:line_length], @html_encoding)
end

#to_s ⇒ Object

Returns the original HTML as a string.



155
156
157
158
159
160
161
 
# File 'lib/premailer/adapter/nokogiri.rb', line 155

def to_s
	if is_xhtml?
		@doc.to_xhtml
	else
		@doc.to_html
	end
end

#write_unmergable_css_rules(doc, unmergable_rules) ⇒ Object

and write it into the body.

doc is an Nokogiri document and unmergable_css_rules is a Css::RuleSet.

Returns an Nokogiri document.



120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/premailer/adapter/nokogiri.rb', line 120

def write_unmergable_css_rules(doc, unmergable_rules) # :nodoc:
  if head = doc.at('head')
    styles = ''
    unmergable_rules.each_selector(:all, :force_important => true) do |selector, declarations, specificity|
      styles += "#{selector} { #{declarations} }\n"
    end    

    unless styles.empty?
      style_tag = "\n<style type=\"text/css\">\n#{styles}</style>\n"

      head.add_child(style_tag)
    end
  else
    $stderr.puts "Unable to write unmergable CSS rules: no <head> was found" if @options[:verbose]
  end
  doc
end